Well my issue was closer to the OP saying both were showing up as one. So have my 1st Pi connected to Cayenne and my scheduling and everything for my multiple projects are working great - you can see the local IP is 192.168.1.25.
Well, once i add the new Pi, you can see it in the Cayenne dashboard view, but its like it's taking over my 1st Pi. Here is the screen shot after the 2nd Pi is installed, you can see the local IP is now 192.168.1.35, and none of my sensors are reachable.
If I unplug the 2nd Pi, reboot the 1st Pi, & remove the 2nd pending Pi on the Cayenne dashboard then everything goes back to normal. I've changed the host names on both pi's before installing Cayenne and both had a fresh copy of Raspbian. I've tried on iOS and on the web.
Both Pi's are Model 3 B and i have a 8 channel relay hooked up to them,